Hi all,

I am working on an ASP.NET project and was wondering if there was a way to use the redirect method in a class outside of the code behind file? The same goes for reading/writing cookies...

The following is a pseudo-walkthrough of what im doing (hopefully to get my question understood better):

I have a login page, default.aspx. The user clicks on the 'Login' button after entering their login and password information.

The button click event resides in the code-behind file. The event creates a UserAction object from another class (which i call the business layer class) which contains the validation rules. I want to be able to read/write cookies, and redirect the user from this class, and not -have- to do it from the code-behind or the "UI" portion of the application.

I've tried looking around MSDN and have found classes such as HttpResponse, HttpRequest, etc but I guess I dont understand how to use these correctly. I have been able to get to what I believe was close, but the problem there was that it required a "prefix" of which I understand being the parts of a url. After selecting the url of my web application, I get an error stating that the connection is in use.

I apologize for rambling so much ;p

Thanks in advance,
Rolandatem

Hi Rolandatem,

You can get access to all the intrinsic ASP.NET objects like Server, Response etc through the HttpContext.Current object which represents the "current" HTTP environment.
For example, you can use the following code to change the value of a cookie from a Class Library project:

System.Web.HttpContext.Current.Response.Cookies["SomeCookie"].Value = "SomeValue";

You may need to add a reference to the System.Web DLL.

Note that using HttpContext.Current ties your business layer to a web application; there is no way to reuse it anymore in, say, a Windows Forms application, more or less breaking the rules for a Class Library.

Also, personally, I would never redirect a user from within a business layer class. Reading from and writing to cookies or sing session variables seems acceptable, but redirecting is confusing. Future developers on your web project probably have no idea that

myCustomer.CheckOrderStatus()

might redirect them away to another page. It's probably a lot cleaner to let the Code Behind handle the redirect, while the business checks the rules for redirecting. E.g. it returns some kind of status or other information, that the Code Behind uses to determine what page to redirect to.

Cheers,

Imar
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Imar Spaanjaars
Everyone is unique, except for me.

Thanks so much for that, it makes more sense now. While trying to figure this out I was wondering how the class created would relate to the page currently in use, so now it make more sense.

Also, I see what you're saying with the redirect issue. At first I figured that would be a business rule, but then after rethinking the issue, if I swapped out the UI to say a windows form, it would break the whole tier structure and would have made it pointless to have the code seperated.

So let me get this straight. My component is just a login validator. It would make more sense the have my login button click event use the business layers validate method and return an integer (which would be the user's db id), and have the code-behind to set the user_id cookie and redirect the user?

Yeah, IMO, redirecting is a presentation thing. In an ASP.NET app, you redirect to another page. In a Windows Forms app, a "redirect" might be a message box or an entirely new form being presented.

There are a few ways to tackle this, depending on your needs. You could, for example, have a Login() method that returns True or False depending on criteria you specify (usually a user name and a password). Then if Login() returns True, you can access the database again and get information for the requested user.

Alternatively, your Login method could return a Customer object (just an example). When the object equals null, login failed. Otherwise, you can use the Customer object for other purposes (get its Id, name, whatever).

E.g.:

Dim myCustomer As Customer = Customer.Login(userName, password)
If myCustomer Is Nothing Then
  ' Login failed
  Response.Redirect("NoWay.aspx")
Else
  ' Login succeeded.
End If

It's a matter of preference. Personally, I would create a separate Login method that returns a Boolean. Then on login success, I'd get the associated Customer record.

HtH,

Imar
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Imar Spaanjaars
Everyone is unique, except for me.